﻿340 
  ANNUAL 
  REPOKT 
  SMITHSONIAN 
  INSTITUTION, 
  192 
  9 
  

  

  some 
  epidemic 
  diseases, 
  it 
  does 
  not 
  follow 
  that 
  the 
  method 
  can 
  prop- 
  

   erly 
  be 
  applied 
  to 
  all 
  of 
  them. 
  After 
  all 
  "similarity" 
  between 
  diseases 
  

   is 
  liable 
  to 
  be 
  superficial; 
  most 
  of 
  the 
  clinical 
  symptoms 
  of 
  infections 
  

   are 
  due 
  to 
  the 
  reaction 
  of 
  the 
  body, 
  and 
  on 
  a 
  priori 
  grounds 
  one 
  

   would 
  expect 
  resemblance 
  between 
  diseases 
  of 
  quite 
  diverse 
  aetiology. 
  

   I 
  conclude, 
  therefore, 
  that 
  we 
  have 
  to 
  admit 
  the 
  possibility 
  that, 
  as 
  in 
  

   the 
  Rous 
  sarcoma, 
  the 
  viruses 
  which 
  we 
  associate 
  with 
  certain 
  

   diseases 
  are 
  not 
  their 
  original 
  causes 
  though 
  they 
  may 
  be 
  the 
  means 
  by 
  

   which 
  they 
  are 
  propagated 
  and 
  carried 
  on. 
  

  

  You 
  will 
  probably 
  say 
  — 
  and 
  I 
  think 
  with 
  a 
  good 
  deal 
  of 
  justifi- 
  

   cation 
  — 
  that 
  it 
  is 
  contrary 
  to 
  all 
  common 
  sense 
  to 
  suggest 
  seriously 
  

   that 
  the 
  viruses 
  of 
  diseases 
  like 
  smallpox, 
  measles, 
  or 
  rabies 
  arise 
  

   anew 
  in 
  each 
  infected 
  person. 
  And 
  it 
  may 
  indeed 
  be 
  nonsense. 
  It 
  

   is 
  evidently 
  more 
  conformable 
  with 
  our 
  general 
  experience 
  and 
  with 
  

   the 
  epidemiological 
  dogma 
  to 
  which 
  we 
  subscribe 
  to 
  lay 
  stress 
  on 
  the 
  

   definite 
  way 
  in 
  which 
  each 
  case 
  can 
  be 
  traced 
  to 
  a 
  preceding 
  case 
  and 
  

   that 
  to 
  another, 
  and 
  so 
  on, 
  explaining 
  such 
  examples 
  of 
  apparently 
  

   spontaneous 
  origin 
  as 
  we 
  m.eet 
  with 
  by 
  carriers 
  and 
  the 
  imperfections 
  

   of 
  our 
  data 
  rather 
  than 
  by 
  the 
  concurrence 
  of 
  a 
  favorable 
  epidemic 
  

   constitution 
  of 
  the 
  atmosphere. 
  With 
  that 
  point 
  of 
  view 
  I 
  quite 
  

   agree; 
  the 
  evidence 
  that 
  in 
  an 
  epidemic 
  something 
  is 
  passed 
  on 
  from 
  

   one 
  case 
  to 
  the 
  next 
  seems 
  extremely 
  strong. 
  But 
  at 
  the 
  same 
  time 
  I 
  

   can 
  not 
  altogether 
  get 
  rid 
  of 
  the 
  uneasy 
  suspicions 
  which 
  intrude 
  when 
  

   I 
  think 
  of, 
  e. 
  g., 
  foot-and-mouth 
  disease, 
  distemper, 
  or 
  labial 
  herpes. 
  

  

  Distemper 
  seems 
  to 
  be 
  everywhere 
  where 
  there 
  are 
  susceptible 
  

   animals, 
  and 
  if 
  the 
  stock 
  of 
  dogs 
  at 
  Mill 
  Hill 
  can 
  be 
  kept 
  free 
  from 
  it 
  

   indefinitely 
  it 
  will 
  be 
  a 
  point 
  of 
  much 
  more 
  than 
  technical 
  interest. 
  

   As 
  to 
  foot-and-mouth 
  disease, 
  in 
  which 
  no 
  material 
  connection 
  be- 
  

   tween 
  one 
  outbreak 
  and 
  another 
  can 
  be 
  discovered, 
  I 
  think 
  that 
  the 
  

   unbiased 
  man 
  in 
  the 
  street 
  would 
  say 
  that 
  the 
  facts 
  showed 
  either 
  that 
  

   the 
  virus 
  was 
  universally 
  dispersed, 
  possibly 
  in 
  some 
  common 
  animal 
  

   (such 
  as 
  the 
  hedgehog 
  ^) 
  other 
  than 
  the 
  cow, 
  or 
  that 
  the 
  disease 
  was 
  

   continually 
  beginning 
  afresh. 
  Labial 
  herpes 
  seems 
  in 
  much 
  the 
  same 
  

   position. 
  Epidemics 
  may 
  be 
  found 
  by 
  ransacking 
  the 
  literature 
  but 
  

   they 
  are 
  certainly 
  not 
  common. 
  Not 
  only 
  has 
  herpes 
  no 
  connection 
  

   with 
  itself 
  but 
  it 
  has 
  a 
  definite 
  association 
  with 
  other 
  diseases— 
  pneu- 
  

   monia 
  and 
  severe 
  catarrhs; 
  its 
  possible 
  relation 
  to 
  human 
  encephalitis 
  

   does 
  not 
  help 
  us 
  — 
  both 
  are 
  blind 
  men. 
  It 
  is 
  possible 
  that 
  the 
  virus 
  is 
  

   an 
  offshoot 
  from 
  the 
  pneumococcus, 
  though 
  when 
  Perdrau 
  looked 
  for 
  

   it 
  in 
  pneumonic 
  lungs 
  he 
  found 
  instead 
  another 
  "agent" 
  which 
  could 
  

   be 
  transmitted 
  through 
  rabbits 
  in 
  series. 
  

  

  ' 
  Mr. 
  Charles 
  Oldham 
  tells 
  me 
  that 
  at 
  the 
  end 
  of 
  the 
  eighteenth 
  and 
  beginning 
  of 
  the 
  nineteenth 
  century 
  

   churchwardens 
  in 
  Hertfordshire 
  put 
  as 
  high 
  a 
  price 
  (4d.) 
  on 
  the 
  head 
  of 
  a 
  hedgehog 
  as 
  on 
  that 
  of 
  a 
  polecat. 
  

   "Urchins" 
  were 
  supposed 
  to 
  do 
  something 
  to 
  cows 
  which 
  diminished 
  the 
  yield 
  of 
  milk 
  and 
  this 
  was 
  trans- 
  

   lated 
  into 
  a 
  belief, 
  still 
  extant, 
  that 
  they 
  sucked 
  the 
  cow's 
  udders 
  when 
  they 
  were 
  lying 
  down. 
  Such 
  ex- 
  

   penses 
  were 
  not 
  lightly 
  incurred 
  in 
  those 
  days. 
  

  

  